“To require surgical anatomical changes as a pre-condition to participation is not necessary to preserve fair competition and may be inconsistent with developing legislation and notions of human rights,” the IOC says.

The new guidelines, however, still require those transitioning from male to female to adhere to a more strict set of rules: they must declare they are transitioning from male to female at least four years before competing in the new category, according to documents published by the IOC. These athletes must also have low levels of testosterone in their system.

“The athlete’s total testosterone level in serum must remain below 10 nmol/L throughout the period of desired eligibility to compete in the female category,” the guidelines say.

The rules for females transitioning to males are less stringent. “Those who transition from female to male are eligible to compete in the male category without restriction,” the guidelines say.

The guidelines will also permit those transitioning who are not eligible to compete in female events to compete in male events instead.